Spine and sacroiliac joint involvement in newly diagnosed inflammatory bowel disease patients - clinical and magnetic resonance imaging findings from a population-based cohort.

BACKGROUND: In IBD patients, co-occurring spondyloarthritis (SpA) leads to poorer outcomes and impaired quality of life, highlighting the importance of early detection and effective treatment. This is the first study to assess the prevalence and distribution of axial symptoms and MRI-detected involvement of the spine and sacroiliac joints (SIJs) in early IBD. METHODS: Newly diagnosed IBD patients from a prospective, population-based cohort were consecutively recruited. Rheumatological interview, clinical, ultrasound and MRI assessment for SIJ and spine inflammatory and structural lesions were made using validated scoring methods and consensus definitions of axial (ax)SpA. RESULTS: Of 110 patients (ulcerative colitis: 70, Crohn's disease: 40, mean age 42 years, 40% male), 48 (44.9%) reported back and/or buttock pain and 10 (9.1%) had inflammatory back pain. Seventeen (16.7%) patients had MRI findings indicative of axSpA; only 10 of these patients had axial symptoms. Inflammatory MRI lesions were present in SIJs and the spine of 27 (26.5%) and 30 (30.3%) patients, respectively. The ASAS classification criteria for axSpA were met in 11 (10%) cases. MRI findings typical of axSpA were associated with peripheral joint and entheseal inflammation detected by ultrasound (p=0.04). No differences in clinical or imaging findings were found between UC and CD patients. CONCLUSION: One-in-six newly diagnosed IBD patients had MRI findings indicative of axSpA. As 40% of these patients were asymptomatic, this suggests that axSpA is underdiagnosed in early IBD. Multidisciplinary collaboration is essential to ensure early detection of axial inflammation and to enable optimal therapy preventing future structural damage and disability.

Occurrence and Prediction of Flare After Tapering of Tumor Necrosis Factor Inhibitors in Patients With Axial Spondyloarthritis.

OBJECTIVE: Patients with axial spondyloarthritis (axSpA) in clinical remission tapered tumor necrosis factor inhibitor (TNFi) therapy according to a clinical guideline. Over a 2-year follow-up period, we aimed to investigate flare frequency, dose at which flare occurred, type of flare, and predictors thereof. METHODS: Patients in clinical remission (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] < 40, physician global score < 40, and without disease activity the previous year) tapered TNFi to two-thirds the standard dose at baseline, half at week 16, one-third at week 32, and discontinued at week 48. Flares were defined as BASDAI flare (BASDAI ≥ 40 and change ≥ 20 since inclusion), and/or clinical flare (development of inflammatory back pain, musculoskeletal or extraarticular manifestations, and/or Ankylosing Spondylitis Disease Activity Score [ASDAS] ≥ 0.9), and/or magnetic resonance imaging (MRI) flare (≥ 2 new or worsened inflammatory lesions). RESULTS: Of 108 patients, 106 (99%) flared before 2-year follow-up: 29 patients (27%) at two-thirds standard dose, 21 (20%) at half dose, 29 (27%) at one-third dose, and 27 (25%) after discontinuation. Regarding type of flare, 105 (99%) had clinical flares, 25 (24%) had BASDAI flares, and 23 (29% of patients with MRI at flare available) had MRI flares. Forty-one patients (41%) fulfilled the Assessment of SpondyloArthritis international Society (ASAS) definition of clinically important worsening (≥ 0.9 increase since baseline). Higher baseline physician global score was an independent predictor of flare after tapering to two-thirds (OR 1.19, 95% CI 1.04-1.41, P = 0.01). Changes in clinical and/or imaging variables in the 16 weeks prior to tapering did not predict flare. CONCLUSION: Almost all (99%) patients with axSpA in clinical remission experienced flare during tapering to discontinuation, but in over half of these patients, flare did not occur before receiving one-third dose or less. Higher physician global score was an independent predictor of flare.

Tapering of TNF inhibitors in axial spondyloarthritis in routine care - 2-year clinical and MRI outcomes and predictors of successful tapering.

OBJECTIVES: In a 2-year follow-up study of patients with axial spondyloarthritis (axSpA) in clinical remission who tapered TNF inhibitor (TNFi) treatment according to a clinical guideline, we aimed to investigate the proportion who successfully tapered/discontinued therapy and baseline predictors thereof. The proportion regaining clinical remission after flare and the progression on MRI/radiography were also assessed. METHODS: One-hundred-and-nine patients (78 [72%]/31 [28%] receiving standard and reduced dose, respectively) in clinical remission (BASDAI < 40, physician global score < 40) and no signs of disease activity the previous year tapered TNFi as follows: to two-thirds of standard dose at baseline, half at week 16, one-third at week 32 and discontinuation at week 48. Patients experiencing clinical, BASDAI or MRI flare (predefined criteria) stopped tapering and escalated to previous dose. Prediction analyses were performed by multivariable regression. RESULTS: One hundred and six patients (97%) completed 2 years' follow-up; 55 patients (52%) had successfully tapered: 23 (22%) receiving two-thirds, 15 (14%) half, 16 (15%) one-third dose and 1 (1%) discontinued. In patients at standard dose at baseline (n = 78), lower physician global score was the only independent predictor of successful tapering (odds ratio [OR] = 0.79 [95% CI: 0.64, 0.93]; P = 0.003). In the entire patient group lower physician global score (OR = 0.86 [0.75, 0.98]; P = 0.017), lower Spondyloarthritis Research Consortium of Canada (SPARCC) Sacroiliac Joint Erosion score (OR = 0.78 [0.57, 0.98]; P = 0.029) and current smoker (OR = 3.28 [1.15, 10.57]; P = 0.026) were independent predictors of successful tapering. At 2 years, 97% of patients were in clinical remission. Minimal changes in imaging findings were observed. CONCLUSION: After 2 years following a clinical guideline, 52% of patients with axSpA in clinical remission had successfully tapered TNFi, only 1% discontinued. Baseline physician global score was an independent predictor of successful tapering.

Quantifying the bone marrow composition of the healthy adult wrist with dual-energy CT.

PURPOSE: Purpose of this study was to investigate Dual-energy CT (DECT) derived virtual non-calcium (VNCa) values for absolute quantification of the bone marrow composition in the wrist. MATERIALS AND METHODS: We prospectively included consecutive adult participants and examined their wrists with DECT. Ranges of VNCa and calcium values were measured in the carpal bones, radius and ulna using a semi-automatic method. Bones with bone marrow edema, assessed by two blinded radiologists, were excluded. After determining optimum parameters for the three-material decomposition, the influence of calcium values, age and sex on VNCa values was assessed using multiple linear regression. RESULTS: 41 participants (Median age 53 years, range 20 years - 88 years, 51 % men) were enrolled and 399 bones assessed. At participant level mean VNCa values were -143 HU (SD 14 HU) using the current parameters for three-material decomposition and -104HU (SD 11 HU) with optimized parameters. There was a strong and significant influence of calcium values on VNCa values with the current parameters (p < 0.001, -0.137 HU[VNCa] / HU[Calcium]). With optimized parameters the calcium values and sex were not statistically significant predictors of VNCa values. Age was a significant, but clinically negligible, predictor (p = 0.03, -0.225 HU / year). CONCLUSIONS: After optimizing three-material decomposition parameters, calcium values, age and sex do not substantially influence virtual non-calcium values, and DECT may therefore be used for absolute quantification of the bone marrow composition - alleviating the need for reference bones or groups.

Incremental diagnostic value of color-coded virtual non-calcium dual-energy CT for the assessment of traumatic bone marrow edema of the scaphoid.

OBJECTIVES: To investigate the diagnostic accuracy of color-coded dual-energy CT virtual non-calcium (VNCa) reconstructions for the assessment of bone marrow edema (BME) of the scaphoid in patients with acute wrist trauma. METHODS: Our retrospective study included data from 141 patients (67 women, 74 men; mean age 43 years, range 19-80 years) with acute wrist trauma who had undergone third-generation dual-source dual-energy CT and 3-T MRI within 7 days. Eight weeks after assessment of conventional grayscale dual-energy CT scans for the presence of fractures, corresponding color-coded VNCa reconstructions were independently analyzed by the same six radiologists for the presence of BME. CT numbers on VNCa reconstructions were evaluated by a seventh radiologist. Consensus reading of MRI series by two additional radiologists served as the reference standard. RESULTS: MRI depicted 103 scaphoideal zones with BME in 76 patients. On qualitative analysis, VNCa images yielded high overall sensitivity (580/618 [94%]), specificity (1880/1920 [98%]), and accuracy (2460/2538 [97%]) for assessing BME as compared with MRI as reference standard. The interobserver agreement was excellent (κ = 0.98). CT numbers derived from VNCa images were significantly different in zones with and without edema (p < 0.001). A cutoff value of - 46 Hounsfield units provided a sensitivity of 91% and specificity of 97% for differentiating edematous scaphoid lesions. Receiver operating characteristic curve analysis revealed an overall area under the curve of 0.98. CONCLUSIONS: Qualitative and quantitative analyses showed excellent diagnostic accuracy of color-coded VNCa reconstructions for assessing traumatic BME of the scaphoid compared to MRI. KEY POINTS: • Color-coded virtual non-calcium (VNCa) reconstructions yield excellent diagnostic accuracy in assessing bone marrow edema of the scaphoid. • VNCa imaging enables detection of non-displaced fractures that are occult on standard grayscale CT. • Diagnostic confidence is comparable between VNCa imaging and MRI.

Dual-energy CT in gout patients: Do all colour-coded lesions actually represent monosodium urate crystals?

BACKGROUND: Dual-energy CT (DECT) can acknowledge differences in tissue compositions and can colour-code tissues with specific features including monosodium urate (MSU) crystals. However, when evaluating gout patients, DECT frequently colour-codes material not truly representing MSU crystals and this might lead to misinterpretations. The characteristics of and variations in properties of colour-coded DECT lesions in gout patients have not yet been systematically investigated. The objective of this study was to evaluate the properties and locations of colour-coded DECT lesions in gout patients. METHODS: DECT of the hands, knees and feet were performed in patients with suspected gout using factory default gout settings, and colour-coded DECT lesions were registered. For each lesion, properties [mean density (mean of Hounsfield Units (HU) at 80 kV and Sn150kV), mean DECT ratio and size] and location were determined. Subgroup analysis was performed post hoc evaluating differences in locations of lesions when divided into definite MSU depositions and possibly other lesions. RESULTS: In total, 4033 lesions were registered in 27 patients (23 gout patients, 3918 lesions; 4 non-gout patients, 115 lesions). In gout patients, lesions had a median density of 160.6 HU and median size of 6 voxels, and DECT ratios showed an approximated normal distribution (mean 1.06, SD 0.10), but with a right heavy tail consistent with the presence of smaller amounts of high effective atomic number lesions (e.g. calcium-containing lesions). The most common locations of lesions were 1st metatarsophalangeal (MTP1), knee and midtarsal joints along with quadriceps and patella tendons. Subgroup analyses showed that definite MSU depositions (large volume, low DECT ratio, high density) had a similar distribution pattern, whereas possible calcium-containing material (high DECT ratio) and non-gout MSU-imitating lesions (properties as definite MSU depositions in non-gout patients) were primarily found in some larger joints (knee, midtarsal and talocrural) and tendons (Achilles and quadriceps). MTP1 joints and patella tendons showed only definite MSU depositions. CONCLUSION: Colour-coded DECT lesions in gout patients showed heterogeneity in properties and distribution. MTP1 joints and patella tendons exclusively showed definite MSU depositions. Hence, a sole focus on these regions in the evaluation of gout patients may improve the specificity of DECT scans.

Dual-Energy CT for Suspected Radiographically Negative Wrist Fractures: A Prospective Diagnostic Test Accuracy Study.

Background Patients with wrist trauma and negative findings on radiographs often undergo additional MRI examinations to assess for radiographically occult fractures. Dual-energy CT may be more readily available than MRI in some settings. Purpose To evaluate the diagnostic test accuracy of dual-energy CT in helping detect bone marrow edema and fracture in participants with wrist trauma and clinical suspicion of a wrist fracture but with negative findings on radiographs. Materials and Methods Adults were prospectively enrolled between January 2018 and November 2018. Wrists were examined with dual-energy CT and MRI, and images were read by four readers who were blinded to clinical information. The presence of bone marrow edema and fracture was rated per bone. The reference standard for bone marrow edema was the combined reading of MRI scans. The reference standard for fracture was a combined reading of MRI and dual-energy CT scans. A fifth radiologist arbitrated results in case of discrepancies. Diagnostic test accuracy was calculated per reader and for readers combined using exact binomial tests. Results Forty-six participants (mean age, 47 years ± 19 [standard deviation]; 24 men [52%]) were enrolled, and 750 bones (50 wrists) were assessed. Dual-energy CT had an average sensitivity of 94% (95% confidence interval [CI]: 80%, 99%; 31 of 33 wrists) and specificity of 65% (95% CI: 38%, 86%; 11 of 17 wrists) in the detection of wrists with bone marrow edema and a sensitivity of 69% (95% CI: 55%, 81%; 36 of 52 bones) and a specificity of 98% (95% CI: 97%, 99%; 682 of 696 bones) in the detection of edema in individual bones. MRI had a sensitivity of 80% (95% CI: 63%, 91%; 28 of 35 wrists) and a specificity of 93% (95% CI: 68%, 100%; 14 of 15 wrists) in helping detect wrists with fractures. Dual-energy CT had a sensitivity of 91% (95% CI: 77%, 98%; 32 of 35 wrists) and a specificity of 87% (95% CI: 60%, 98%; 53 of 60 wrists) in helping detect wrists with fractures. McNemar tests showed no significant differences between MRI and dual-energy CT (P = .07 to >.99) for all readers. Conclusion Dual-energy CT had a high sensitivity and a moderate specificity in the detection of bone marrow edema of the wrist. Dual-energy CT had high sensitivity and specificity in depicting fractures of the wrist in patients with suspected wrist fractures and negative findings on radiographs. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Fukuda in this issue.

Optimising dual-energy CT scan parameters for virtual non-calcium imaging of the bone marrow: a phantom study.

BACKGROUND: We investigated the influence of dose, spectral separation, pitch, rotation time, and reconstruction kernel on accuracy and image noise of virtual non-calcium images using a bone marrow phantom. METHODS: The phantom was developed at our institution and scanned using a third-generation dual-source dual-energy CT scanner at five different spectral separations by varying the tube-voltage combinations (70 kV/Sn150 kV, 80 kV/Sn150 kV, 90 kV/Sn150 kV, and 100 kV/Sn150 kV, all with 0.6-mm tin filter [Sn]; 80 kV/140 kV without tin filter) at six different doses (volume computed tomography dose index from 1 to 80 mGy). In separate experiments, rotation times, pitch, and reconstruction kernels were varied at a constant dose and tube voltage. Accuracy was determined by measuring the mean error between virtual non-calcium values in the fluid within and outside of the bone. Image noise was defined as the standard deviation of virtual non-calcium values. RESULTS: Spectral separation, dose, rotation time, or pitch did not significantly correlate (p > 0.083) with mean error. Increased spectral separation (rs-0.96, p < 0.001) and increased dose (rs-0.98, p < 0.001) correlated significantly with decreased image noise. Increasing sharpness of the reconstruction kernel correlated with mean error (rs 0.83, p = 0.015) and image noise (rs 1.0, p < 0.001). CONCLUSIONS: Increased dose and increased spectral separation significantly lowered image noise in virtual non-calcium images but did not affect the accuracy. Virtual non-calcium reconstructions with similar accuracy and image noise could be achieved at a lower tube-voltage difference by increasing the dose.

The effects of rotation on radiological parameters in the spine.

BACKGROUND: Vertebral rotation in straight spines or in spines with small scoliosis may potentially affect measurement of radiological parameters in both the frontal and sagittal plane. This is important, since it could lead to potential misdiagnosis of scoliosis and other clinical consequences, and until now, this has not been examined. PURPOSE: To examine the effect of axial vertebral rotation of the spine on measurement of common radiological parameters. MATERIAL AND METHODS: Reconstructions from computed tomography scans of 40 consecutive included and anonymized patients with straight spines or small scoliosis. Fourteen sagittal and coronal reconstructions covering the whole pelvis and spine were executed. Radiographic parameters in both the frontal and sagittal plane were measured blinded and separately by three doctors. These parameters were evaluated for inter-rater reliability using intraclass correlation coefficient and mixed model analysis for the effects of rotation. The parameters were also analyzed sub-stratified according to "Lenke's classification" and 15 sub-categories of thoracic and lumbar Cobb's angle (CA). RESULTS: Vertebral rotation in general does not have any significant effects in both the frontal and sagittal plane. However, there are significant effects on CA and spinopelvic radiologic parameters in extreme rotation or for larger scoliosis. Inter-rater reliability was very good to good. CONCLUSION: In conclusion, axial spinal rotation does not influence common radiological parameters in the frontal and sagittal plane, except in cases of extreme rotation or large scoliosis for selected parameters; thus, this does not lead to potential misinterpretation in scoliosis diagnosis, treatment, or research.

The role of the paravertebral muscles in adolescent idiopathic scoliosis evaluated by temporary paralysis.

BACKGROUND: Muscle imbalance has been suggested as implicated in the pathology of adolescent idiopathic scoliosis (AIS). The specific "pathomechanic" role of the paravertebral muscles as being scoliogenic (inducing scoliosis) or counteracting scoliosis in the initial development and maintenance of this spinal deformity has yet to be clarified in humans. In the present study, we investigated the radiographic changes of temporal paralysis using botulinum toxin A as localized injection therapy (ITB) in the psoas major muscle in AIS patients. METHODS: Nine patients with AIS were injected one time with ITB using ultrasonic and EMG guidance in the selected spine muscles. Radiographic and clinical examinations were performed before and 6 weeks after the injection. Primary outcome parameters of radiological changes were analyzed using Wilcoxon signed-rank test and binomial test, and secondary outcome parameters of short- and long-term clinical effects were obtained. RESULTS: Significant radiological corrective changes were seen in the frontal plane in the thoracic and lumbar spine as well as significant derotational corrective change in the lumbar spine according to Cobb's angle measurements and to Nash and Moe's classification, respectively. No serious adverse events were detected at follow-up. CONCLUSIONS: In conclusion, this study demonstrated that the psoas major muscle do play a role into the pathology in adolescent idiopathic scoliosis by maintaining the curvature of the lumbar spine and thoracic spine. TRIAL REGISTRATION: EudraCT number 2008-004584-19.

The Effect of Botulinum Toxin A Injections in the Spine Muscles for Cerebral Palsy Scoliosis, Examined in a Prospective, Randomized Triple-blinded Study.

STUDY DESIGN: A prospective, randomized triple-blinded cross-over design treating with either botulinum toxin A (BXT) or saline (NaCl). OBJECTIVE: To examine the efficacy of BTX treatment in cerebral palsy scoliosis (CPS). SUMMARY OF BACKGROUND DATA: Intramuscular injections with BTX have been used off label in treating CPS. 1 prospective study has been conducted, demonstrating in both radiological and clinical improvement, whereas showing no side effects or complications. METHODS: Subjects (brace-treated CPS between 2 and 18 yr) were injected using ultrasonic-guidance with either NaCl or BTX in selected spine muscles with 6 mo intervals (block randomization, sealed envelope). Radiographs of the spine and clinical follow-up were captured before and 6 weeks after each injection. Primary outcome parameter was radiological change in Cobb angle, where a 7° change was regarded as an effect (1 SD). Radiological parameters were measured before and 6 weeks after treatment by 3 experienced doctors separately. Moreover, clinical results were evaluated by the pediatric quality of life score and systematic open questioning of the parents about the child's wellbeing. Subjects, researchers, and monitors were blinded during the trial. Appropriate permissions (2008-004584-19) and no funding were obtained. RESULTS: 16 cerebral palsy patients (GFMCS III-V) with CPS were consecutively included, whereas 6 patients were excluded. There were no drop-outs to follow-up, but 1 possible serious adverse event of pneumonia resulting in death was recorded and the study was terminated. No significant radiological or clinical changes were detected when compared with NaCl injections using Wilcoxon matched pair signed-rank test. CONCLUSION: No positive radiological or clinical effects were demonstrated by this treatment, except for the parent's initial subjective but positive appraisal of the effect. However, the study was terminated due to 1 possible severe adverse event and scheduled numbers needed to treat (hence power) were not reached. LEVEL OF EVIDENCE: 1.

Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis.

BACKGROUND AND PURPOSE: Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE). METHODS: We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10-17 years postoperatively. Median age at surgery was 12 (10-14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up. RESULTS: Median preoperative Southwick angle was 22o (IQR: 12-27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade>1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49-56) and median mental score was 56 (IQR: 54-58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution. Median WOMAC score was 100 (IQR: 84-100). INTERPRETATION: In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise.

The alignment of the knee joint in relationship to age and osteoarthritis: the Copenhagen Osteoarthritis Study.

INTRODUCTION: The aim of the present study was to describe the changes in the axis of the knee joint in both radiologically osteoarthritic and non-osteoarthritic knees, on the basis of angles measurable in standardized clinical short knee radiographs, in a cross sectional study of an epidemiological cohort. DESIGN: From the third inclusion of the Copenhagen City Heart Study, 4,151 subjects were selected for standardized radiography of the knees. After censuring the inclusion, the resulting cohort was comprised of 3,488 individuals. Images were analyzed for radiological knee joint osteoarthritis (OA) and the anatomical femorotibial axis of the knee joint was measured. RESULTS: The prevalence of knee joint OA in males was 27.9% and 27.5%, for the left and right knees respectively. In females this was 32.8% and 36.4%. The mean knee joint angles were 4.11° in males; and 5.45° in females. A difference of 1.3° was found between the genders. In non-osteoarthritic knees the increase in valgus orientation in relationship to increasing age was found to be 0.03° and 0.04° per year, respectively, for males and females. Likewise, Kellgren and Lawrence found that OA was seen to influence a shift towards varus of 0.55°-0.76° per level of OA. CONCLUSION: Stratification in accordance with morphological severity of OA documented a clear tendency for the axis of the diseased knees to depart from the mean, primarily in the direction of varus. In knees exhibiting no signs of radiographic osteoarthritis we found a significant relationship between increasing age and a shift in the anatomical axis in the direction of valgus.

The prevalence of predisposing deformity in osteoarthritic hip joints.

It is becoming increasingly evident that hip joint deformities may be major contributors to the development of osteoarthritis, and the term 'idiopathic osteoarthritis' may be inappropriate in many cases. Our study cohort was derived from the Copenhagen Osteoarthritis Sub-study, a cross sectional population-based database of 4151 individuals, all of whom had a standard anteroposterior weight-bearing pelvic radiograph taken. Hip joints were classified according to type and degree of deformity. We defined hip osteoarthritis by a minimum joint space width of < or = 2 mm. This cut-off has a significant relationship in both sexes with the clinical presentation. The study cohort which fulfilled these inclusion criteria consisted of 322 females (149 right hips and 173 left hips) and 162 males (77 right hips and 85 left hips) with osteoarthritis. We found an overall prevalence of predisposing hip deformities in females of 62.4% and in males of 78.9%. Minor and major deformities showed the same prevalence. Both sexes had a comparable prevalence of minor and major hip joint deformity, except for pistol grip deformity, which was more prevalent in men. We concluded that 'idiopathic osteoarthritis' is uncommon, and that even minor predisposing deformities are associated with hip osteoarthritis.

Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey.

BACKGROUND: Although the clinical consequences of femoroacetabular impingement have been well described, little is known about the prevalence of the anatomical malformations associated with this condition in the general population, the natural history of the condition, and the risk estimates for the development of osteoarthritis. METHODS: The study material was derived from a cross-sectional population-based radiographic and questionnaire database of 4151 individuals from the Copenhagen Osteoarthritis Substudy cohort between 1991 and 1994. The subjects were primarily white, and all were from the county of Østerbro, Copenhagen, Denmark. The inclusion criteria for this study were met by 1332 men and 2288 women. On the basis of radiographic criteria, the hips were categorized as being without malformations or as having an abnormality consisting of a deep acetabular socket, a pistol grip deformity, or a combination of a deep acetabular socket and a pistol grip deformity. Hip osteoarthritis was defined radiographically as a minimum joint-space width of 0.13). A deep acetabular socket was a significant risk factor for the development of osteoarthritis (risk ratio, 2.4), as was a pistol grip deformity (risk ratio, 2.2). Acetabular dysplasia and the subject's sex were not found to be significant risk factors for the development of hip osteoarthritis (p = 0.053 and p = 0.063, respectively). The prevalence of hip osteoarthritis was 9.5% in men and 11.2% in women. The prevalence of concomitant malformations was 71.0% in men with hip osteoarthritis and 36.6% in women with hip osteoarthritis. CONCLUSIONS: In our study population, a deep acetabular socket and a pistol grip deformity were common radiographic findings and were associated with an increased risk of hip osteoarthritis. The high prevalence of osteoarthritis in association with malformations of the hip joint suggests that an increased focus on early identification of malformations should be considered.

Case definitions of knee osteoarthritis in 4,151 unselected subjects: relevance for epidemiological studies: the Copenhagen Osteoarthritis Study.

INTRODUCTION: The aims of the present study were threefold: to examine the distribution of knee joint osteoarthritis in a large, standardized radiological study; to examine the relationships between self reported knee pain and radiological OA; and to examine the natural history of radio-morphological change over age in individuals without radiological features of OA. MATERIALS AND METHODS: The Copenhagen Osteoarthritis Study - COS is a substudy of the Copenhagen City Heart Study, a longitudinal regional health survey. From the third inclusion of the CCHS (1992-1994) 4,151 subjects were selected for subsequent standardized radiography of the pelvis, the knees, the hands, the wrists, and the lumbar spine. Images were analyzed and knee joint osteoarthritis (OA) was classified according to the radiographic atlas of Kellgren and Lawrence. Joint space width (JSW) was measured at three sites within both the medial and the lateral compartment. RESULTS: For the entire cohort the prevalence of radiological knee joint OA of all grades was 38.7% for men and 44.2% for women. Age stratification documented increasing knee joint OA both in regard to prevalence and morphological severity. Knee pain was universally correlated to the Kellgren and Lawrence severity of OA. In a subgroup with no features of radiological OA, a significant and linear decline in JSW with increasing age was found. CONCLUSION: We found a clear relationship between self-reported knee pain and radiological osteoarthritis. Pain was proportionally related to the severity of change. We also demonstrated a significant diminishing of joint space width with increasing age in individuals without apparent radiological degeneration.

A new measurement for posterior tilt predicts reoperation in undisplaced femoral neck fractures: 113 consecutive patients treated by internal fixation and followed for 1 year.

BACKGROUND AND PURPOSE: Preoperative posterior tilt in undisplaced (Garden I-II) femoral neck fractures is thought to influence rates of reoperation. However, an exact method for its measurement has not yet been presented. We designed a new measurement for posterior tilt on preoperative lateral radiographs and investigated its association with later reoperation. PATIENTS AND METHODS: A consecutive series of 113 patients, > or = 60 years of age with undisplaced (Garden I-II) femoral neck fractures treated with two parallel implants, was assessed regarding patient characteristics, radiographs, and rate of reoperation within the first year. In a subgroup of 50 randomly selected patients, reliability tests for measurement of posterior tilt were performed. RESULTS: Intra- and interclass coefficients for the new measurement were > or = 0.94. 23% (26/113) of patients were reoperated and increased posterior tilt was an accurate predictor of failure (p = 0.002). 14/25 of posteriorly tilted fractures > or = 20 degrees were reoperated, as compared to 12/88 of fractures with less tilt (p < 0.001). In multiple logistic regression analysis including sex, age, ASA score, cognitive function, new mobility score, time from admission to operation, surgeon's expertise, postoperative reduction, and implant positioning, a preoperative posterior tilt of > or = 20 degrees was the only significant predictor of reoperation (p < 0.001). INTERPRETATION: The new measurement for posterior tilt appears to be reliable and able to predict reoperation in patients with undisplaced (Garden I-II) femoral neck fractures.

[Low back degeneration and radiology]. / Laenderyggens degeneration og radiologi.

Low back pain (LBP) is one of the most common conditions, and at the same time one of the most complex nosological entities. The lifetime prevalence is approximately 80%, and radiological features of lumbar degeneration are almost universal in adults. The individual risk factors for LBP and significant relationships between radiological findings and subjective symptoms have both been notoriously difficult to identify. The lack of consensus on clinical criteria and radiological definitions has hampered the undertaking of properly executed epidemiological studies. The natural history of LBP is cyclic: exacerbations relieved by asymptomatic periods. New imaging modalities, including the combination of MR imaging and multiplanar 3-D CT scans, have broadened our awareness of possible pain-generating degenerative processes of the lumbar spine other than disc degeneration.